JP2003252018A - Vehicle height adjusting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of suppressing temporary and abrupt change of height of a frame supported by an air spring due to loading and unloading of cargoes to provide the device allowing effective use even when heights of a platform used for loading and unloading cargoes differ. <P>SOLUTION: At the time of loading and unloading works, a spacer is inserted between an axle beam and the frame, and pneumatic pressure of the air spring is reduced. Pneumatic pressure is adjusted to low pressure so that load of the frame is supported through the spacer during a period of the loading and unloading works. Furthermore, a plurality of spacers having different heights are prepared in one spacer unit. A position of the spacer unit is changed by operation by matching with height of the platform in a cargo loading and unloading place, and one of a plurality of prepared spacers is selected for use. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in a vehicle equipped with an air spring. INDUSTRIAL APPLICABILITY The present invention is used for a lorry, a towed vehicle, and other vehicles for loading and unloading cargo. The present invention relates to a device for temporarily suppressing a change in vehicle height when loading and unloading cargo.

[0002]

2. Description of the Related Art In a vehicle equipped with an air spring, the air pressure is adjusted whenever the weight of a cargo or the like mounted on the vehicle changes, so that the vehicle height (height from the axle to the chassis) is always constant. Automatically controlled and controlled. However, it takes a certain amount of time to adjust the air pressure, and during operations such as loading or unloading large cargo,
The vehicle height may fluctuate temporarily. In particular, when using an auxiliary device such as a forklift or a large cart to load and unload cargo, the vehicle height drops sharply at the moment the auxiliary device gets into the chassis, and at the moment the auxiliary device leaves the chassis. May jump up greatly. When the air spring is working effectively, the vehicle height will return to the original reference value after a few seconds, but there will be situations where it cannot be supported by the human power of the site, such as load collapse due to temporary fluctuations. Sometimes.

In order to avoid such an inconvenience regarding the air spring, a technique disclosed in Japanese Patent Application Laid-Open No. 2001-219724 (Applicant: Mitsubishi Motors, first publication) is known. This has a structure in which a removable stopper is provided between the chassis and the axle. That is, when loading cargo, the position of the stopper is displaced so as to be effective between the chassis and the axle, and the vehicle height is limited by the height regulated by the stopper even if the load increases. To use. It is described that while the vehicle is traveling, the stopper is pulled up so that the air spring is effective. When cargo is loaded by this structure, the chassis supported by the air spring gradually lowers and is held in a state in which the spring action regulated by the stopper is not exerted.

Further, in Japanese Unexamined Patent Publication No. 2001-192200 (applicant: Furukawa Kikinzoku, second publication) and Japanese Utility Model Laid-Open No. 2-115509 (applicant: Nissan Diesel, third publication) There is also known a device in which the air spring is mechanically locked during the loading and unloading work to prohibit the vehicle height adjustment even if the load applied to the air spring changes.

Further, the applicant of the present application, during the loading and unloading work of the vehicle, a control method such as finely adjusting the air pressure of the air spring and temporarily fixing a shock absorber provided in parallel with the air spring. And a patent application for the device (JP 2001-47836A,
JP-A-2001-88526 and JP-A-2001-97
No. 018, fourth to sixth publications).

[0006]

In the structure disclosed in the above-mentioned first publication, when a load is suddenly increased by utilizing a stopper at the time of loading of cargo, the sinking of the chassis causes the sinking at the position of this stopper. It is a regulated structure, and the structure of this device is considered to be effective even when cargo is loaded (when the load increases), but when the cargo is unloaded (when the load decreases) Has the drawback of not being effective. That is, it is not clear how to install a stopper for controlling the vehicle height when a large amount of cargo is loaded. Although the first publication describes that the air suspension is locked by a stopper, it does not explain the idea of lowering the air pressure of the air spring when using the stopper when loading and unloading cargo. Therefore, the device described in this first publication is ineffective when the load on the bed is sharply reduced. It is considered that when the forklift boarded on the bed of the towed vehicle grips the cargo and the forklift separates from the bed to the platform, it is impossible to prevent the bed from suddenly jumping up due to the air pressure of the air spring.

Further, in the structure disclosed in the above-mentioned first publication, the height at which the chassis is temporarily fixed is determined by the size of the stopper, and the height cannot be selected. There is. That is, when the vehicle is stopped by contacting the cargo loading platform,
It is good if the chassis height exactly matches the height of the platform, but if the height is not suitable it cannot be adjusted to fit. Therefore, this device cannot be used when the heights of the platforms do not match, or an auxiliary member such as an appropriate bridge plate is required between the platforms and the chassis.

What is disclosed in the above-mentioned second publication is
Although the height can be adjusted, its mechanical structure is complicated, and if a lock mechanism for a large vehicle is designed by this structure, the device itself becomes a large and heavy structure. Moreover, the adjustment operation is not easy. Particularly, it is considered that a fairly complicated operation is required to adjust the height of the chassis with a heavy load. Further, in the device disclosed in the above-mentioned third publication, the fixing height cannot be adjusted, and the device itself becomes a corresponding heavy object.

Further, by utilizing the techniques disclosed in the above-mentioned fourth to sixth publications, the vehicle height can be finely adjusted as the weight of the load changes, and the change is prohibited if necessary. However, this device includes a control device, which increases the cost of the entire device. It cannot be used in vehicles that are required to be provided to users at extremely low prices, such as towed vehicles.

A device for temporarily controlling the vehicle height for use in a freight vehicle or a towed vehicle needs to have a structure that can withstand a corresponding load, and must be used safely. I won't. While unloading cargo,
It should not be able to withstand changes in load and become damaged.

The present invention has been made in view of such a background, and provides an apparatus having a simple and simple structure, and an apparatus for temporarily suppressing a vehicle height change and a control method thereof. With the goal. SUMMARY OF THE INVENTION It is an object of the present invention to provide a control method in which the bogie of the chassis does not jump up when the cargo is loaded or unloaded.
It is a further object of the present invention to provide a device and a method capable of gradually selecting the height of the chassis to be temporarily fixed. The present invention aims to provide a device that is simple and simple to operate. An object of the present invention is to provide a device having structurally excellent safety. The present invention is
An object of the present invention is to provide a device capable of temporarily suppressing a change in vehicle height at an extremely low cost. An object of the present invention is to provide a device that can be easily attached to an existing towed vehicle or the like later.

[0012]

According to the present invention, a beam (2) supporting an axle (1) and an air spring (4) interposed between the beam (2) and the chassis (3) are provided. In the vehicle height adjusting device including means for adjusting the air pressure of the air spring (4), a plurality of n different heights for restricting the minimum distance between the chassis (3) and the beam (2) are provided. A spacer unit (6) provided with a spacer (5), and means for changing the position of the spacer unit (6) so that one of the spacers (5) is effective. To do.

The numbers in the parentheses above are reference numbers in the embodiment drawings described later. This is given to facilitate understanding of the configuration of the present invention, and is not intended to limit the understanding of the configuration of the present invention to the examples. The same applies to the description that follows.

That is, in the structure of the present invention, the spacer (5) for restricting the vehicle height is movably sandwiched between the chassis (3) and the beam (2). Control the air pressure in the air spring (4).
A plurality of spacers (5) having different heights are prepared as one unit, and one of them is selectively used. When loading and unloading luggage, the most suitable height is selected and set so that this one spacer (5) is effective according to the height of the platform at that time and other conditions at the site. After setting the selected spacer (5), the air pressure of the air spring (4) is reduced. And the chassis is this spacer (5)
The load (unloading work) is carried out by contacting the beam (2) via the spacer, that is, the load of the chassis is supported by the axle (1) via the spacer. The air spring (4) is in principle not in a valid state during the loading and unloading work. Therefore, even if the load on the chassis suddenly changes due to getting on or off the forklift,
The air spring is not controlled accordingly. When the loading and unloading work of the luggage is completed, the chassis is lifted by returning the air pressure of the air spring (4) to a predetermined value, and the load applied to the used spacer is removed. In this state, the spacer unit (6) is moved to a position where none of the spacers is effective and the vehicle is run.

In the present invention, the spacer (5) is interposed between the beam (2) supporting the axle (1) and the chassis (3) so that the vehicle height is the same as that of the spacer (5) during the loading and unloading of cargo. The air pressure of the air spring (4) may be adjusted to a small value so as to be maintained at a value regulated by (4). This includes the meaning that the air pressure of the air spring is adjusted to a small value in consideration of the load that is temporarily released from the platform. For example, during loading and unloading of cargo, when a large amount of cargo is temporarily separated from the bed by the forklift, the load (the load of the forklift and the load of the cargo gripped by the forklift) may be released at that time. The vehicle height supported by the spacer is maintained, and the air pressure is preferably adjusted to be sufficiently small so that the chassis does not bounce up due to the action of the air spring. With this configuration, the bouncing up phenomenon of the chassis during the cargo handling work can be eliminated.

It is appropriate that the number n of spacers (5) provided in one spacer unit (6) is 3 to 4. By appropriately designing the height of each spacer (5) with any of these numbers, it is possible to satisfy the practical platform height any time. Moreover, the spacer having the lowest height is set so as to be located just above the axle (1) while the vehicle is traveling, and the displacement limit value of the air spring during traveling is regulated. It can also be used as a stopper.

The means for changing the position of the spacer unit (6) may be an electric motor, a pneumatic cylinder, or a manual operation. Of these, the structure in which the position of the spacer unit (6) is changed manually by a manual lever or handle is the simplest structure and can be realized at low cost. This is particularly effective when the present invention is applied to a towed vehicle. In a towed vehicle, in order to increase the operating rate of the tow vehicle, loading and unloading of the luggage may be performed with the tow vehicle disconnected. When the towing vehicle is disconnected, the air pressure source and power supply cannot be obtained freely. Therefore, a structure in which the position of the spacer unit (6) is changed and set by manual operation is useful.

[0018]

Embodiments of the present invention will be described in more detail with reference to the drawings. FIG. 1 is a side view showing the structure of the first embodiment device of the present invention. The axle 1 is supported by a beam 2, and an air spring 4 is interposed between the beam 2 and the chassis 3 so that vibrations generated on the axle 1 due to unevenness of the road surface during traveling are not directly transmitted to the chassis 3. It is configured. The air pressure of the air spring 4 is supplied from an adjusting means (not shown) by an automatic control system, and is adjusted and controlled so that the vehicle height is always maintained in a constant range. Since this automatic control system is a well-known device and is not directly related to the present invention, its detailed description is omitted here. Further, a shock absorber 8 is mechanically connected in parallel with the air spring 4 and is controlled so that the vibration by the air spring 4 does not last long.

Here, a feature of the present invention is that a plurality of spacers 5 having different heights for restricting the minimum distance between the chassis 3 and the beam 2 are provided below the chassis 3.
Moreover, the plurality of spacers 5 are provided in one spacer unit 6, and by changing the position of the spacer unit 6, one of the plurality of spacers 5 is made effective. And means for changing the position of. The plurality n is "3" in this first embodiment device. In this first embodiment device, the means for changing the position has a structure including an electric motor unit 7. The spacer unit 6 can be provided on each of the left and right wheels, but it is economical to provide only one spacer unit at approximately the center of the axle 1. If there is no suitable frame or member to which the spacer unit 6 is attached in the center of the chassis 3 such as the towed vehicle, the appropriate steel member is laid between both frames and the steel member is used. Can be configured to be attached to. The circumference indicated by the alternate long and short dash line in the figure is the outermost shape of the wheel.

The device thus constructed is used when a vehicle arrives at a collection base or the like to load and unload cargo. When the vehicle stops near the platform of the collection base, the driver recognizes the height of the platform and operates the switch (not shown) to rotate the motor in the forward or reverse direction. Of the spacers 5 prepared individually, the one with the most suitable height is
The adjustment is controlled so that it is located right above the beam 2. Then, a lever (not shown) of an air pressure control valve provided in a passage for supplying air pressure to the air spring 4.
Is operated to lower the air pressure of the air spring 4 to lower the chassis 3 and bring the selected spacer 5 into contact with the beam 2. Loading and unloading of luggage is performed in this state.

In this state, the chassis 3, that is, the bed of the vehicle is supported by the axle 1 via the spacer 5, and the height of the bed does not change even if the weight changes due to loading and unloading of luggage. A forklift is used for loading and unloading work, and even if the forklift gets into or out of the bed, the height of the bed does not change abruptly.

When the loading and unloading work of the luggage is completed, the driver operates to supply proper air pressure to the air spring 4 to restore the state where the load is supported by the air spring 4. Further, the power source of the motor unit 7 is operated to return the position of the spacer unit 6 to the original position. In this example, this original position is exactly the position shown in FIG. 1, and the spacer 5 having the smallest height is located directly above the beam 2. In this state, the traveling of this vehicle can be started.

As described above, according to the configuration of the present invention, when loading and unloading luggage at a collection base or a warehouse, the vehicle height, that is, the height of the loading platform is fixed according to the height of the platform or the like at that location. Can be made. The structure of the present invention is extremely simple, and this device can be provided inexpensively. Even when a device is added to an existing vehicle for modification, the effective device can be provided at a very low cost. Since this device is inexpensive, it can be installed in many vehicles as standard specifications.

In the above example, an electric motor is used to change the position of the spacer unit 6, but it is also possible to design the displacement mechanism of the spacer unit 6 using a pneumatic cylinder. . In this case, the air pressure source used for the pneumatic cylinder can branch and use the air pressure for the air spring.

FIG. 2 is a structural diagram of a second embodiment device of the present invention. This second embodiment device is provided with a manual handle 9 and a gear unit 10 as means for changing the position of the spacer unit 6. Handle 9
By rotating the counterclockwise or clockwise, the spacer unit 6 moves to the left and right in the figure as shown by the arrow, and the spacer 5 of the most suitable height is located right above the beam 2. Can be adjusted as

By employing a manual structure that does not use a special power in this way, the mechanism of the present invention can be used even in a state where a power source or air pressure cannot be obtained. Further, the device can be provided at low cost by adopting the manual structure.
In particular, in a towed vehicle that is often disconnected from the towed vehicle for loading and unloading work, power and air pressure may not be obtained freely, so the moving mechanism of the spacer unit 6 may be a manual structure. It is valid. It is also possible to use these powers when power and air pressure are available, and to design the position of the spacer unit 6 to be manually changed when used without power and air pressure. In order to modify the existing vehicle to carry out the present invention, the structure is further simplified by adopting the manual structure.

[0027]

According to the present invention, a device for temporarily suppressing changes in vehicle height can be obtained with a simple and simple structure. According to the present invention, since the height of the chassis to be temporarily fixed can be selected in stages, the range of application can be expanded and the height of the chassis can be effectively increased according to the height of the platform at the loading work place and other environments. Regulating devices are available. The device of the present invention is simple and simple to operate. Since the device of the present invention has a simple structure, it is possible to design an inexpensive device having excellent safety. The device of the present invention requires a small number of parts and can be easily attached to an existing towed vehicle or the like by a modification work.

[Brief description of drawings]

FIG. 1 is a structural diagram of a device according to a first embodiment of the present invention.

FIG. 2 is a structural diagram of a second embodiment device of the present invention.

[Explanation of symbols]

1 axle Two beams 3 chassis 4 air spring 5 spacers 6 Spacer unit 7 Motor unit 8 shock absorbers 9 handle 10 gear unit

Claims (5)

[Claims] 1. A vehicle height adjusting device comprising a beam supporting an axle, an air spring interposed between the beam and the chassis, and means for adjusting the air pressure of the air spring. A spacer unit provided with a plurality of n spacers having different heights for restricting the minimum distance from the beam; and means for changing the position of the spacer unit so that one of the spacers is effective. A vehicle height adjusting device characterized by being provided. 2. The vehicle height adjusting device according to claim 1, wherein n is 3. 3. The vehicle height adjusting device according to claim 1, wherein the means for controlling the position includes an electric motor. 4. The vehicle height adjusting apparatus according to claim 1, wherein the means for controlling the position includes a pneumatic cylinder. 5. The vehicle height adjusting device according to claim 1, wherein the means for controlling the position includes a manual lever.